CENTER FOR VETERINARY BIOLOGICS NOTICE 18-13

TO: Biologics Licensees, Permittees, and Applicants

 Directors, Center for Veterinary Biologics

 Veterinary Services Leadership Team

FROM: Byron Rippke

 Director

SUBJECT: Labeling of Vaccines Containing Porcine Circovirus Type 2 

I. PURPOSE

This notice informs licensees, permittees, and applicants of the current Center for 

Veterinary Biologics (CVB) policy concerning disclosure of Porcine Circovirus 

Type 2 genotypes used in vaccines and efficacy challenges.

II. BACKGROUND

Porcine Circoviruses are small non-enveloped circular ssDNA viruses of the genus 

Circovirus and family Circoviridae. Porcine Circovirus Type 1 (PCV1) is 

considered non-pathogenic, whereas Porcine Circovirus Type 2 (PCV2) causes a

complex of porcine circovirus-associated diseases (PCVAD) in pigs. PCV2 is 

divided into at least six genotypes, PCV2a through PCV2f, as a result of genotype 

shifts in the ORF2 genome.

1,2 Although PCV2a was previously considered to be the 

most prominent, recent publications from 2003 onward, have reported that PCV2b 

and PCV2d seem to be more virulent and are prominently circulating in pigs2. In 

addition, there appears to be partial cross-protection among some currently 

identified PCV2 genotypes. 

Due to the emergence of new PCV2 genotypes and their impact on vaccine 

effectiveness, the CVB has determined that it is appropriate to disclose genotype

information on product labeling.

 1 Brendan, D., Wang, X., Dvorak, C. M. T., Marthaler, D., and Murtaugh, M. 2017, Virus Research 217: 32-37.2 

2 Karuppannan, A. K., and Opriessnig, T. 2017, Viruses 9: 99; doi: 10.3390/v9050099

Animal and Plant

Health Inspection

Service

Veterinary Services

Center for Veterinary 

Biologics

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PO Box 844

Ames, IA 50010

(515) 337-6100
CENTER FOR VETERINARY BIOLOGICS NOTICE 18-13

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III. ACTION (or POLICY)

All labels and Section VI of the Outlines of Production for products containing PCV2 

should state the genotype(s) of PCV contained in the product (e.g. PCV2a, PCV2b, 

PCV2d, etc.), as described in Veterinary Services Memorandum (VSM) 800.54, Section 

III.H. Likewise, in the Individual Study Summaries (ISS)s firms must specify the 

genotype(s) of PCV for which efficacy has been demonstrated by including the genotype 

of challenge viruses used in approved pivotal efficacy studies. A general single tier claim

will be allowed for any licensed product, e.g.: 

“This product has been shown to be be effective for the vaccination of healthy pigs X 

days of age or older against Porcine Circorvirus 2.”

Alternatively, specific claims for genotypes against which efficacy has been individually 

demonstrated will also be allowed, e.g.:

“This product has been shown to be be effective for the vaccination of healthy pigs X 

days of age or older against Porcine Circorvirus 2a, 2b, and 2d.”

IV. IMPLEMENTATION/ APPLICABILITY

The CVB is requiring that firms amend the Outlines of Production, labels, and ISSs for 

previously licensed products within one year from the date of this Notice. The CVB will 

update the related Product Compilation Summaries (PCS)s accordingly. Firms must 

disclose PCV genotypes contained in the vaccine on labels and in Outlines, and disclose 

the genotype of challenge strains used to demonstrate efficacy in ISSs, so the CVB can 

generate the appropriate PCSs.